The present disclosure relates to biometric sensor devices, and more specifically to a biometric sensor such as a fingerprint sensor which includes an integrated visual indicator.
One relatively common biometric sensing device today is the fingerprint sensor. These devices are used in controlling access to electronic devices such as computers and mobile phones, safes, buildings, vehicles, etc. by scanning a user's fingerprint and comparing it to an authenticating set of fingerprint images. If the proffered (live) fingerprint to be authenticated matches one within a set of pre-enrolled authorized fingerprints, access may be granted. Fingerprint sensors may be stand-alone devices such as PC peripherals, or may be integrated into the devices over which they control access.
There are various motivations to provide a visual indicator in association with a fingerprint sensor. A first set of motivations are operational. For example, cues may be provided to a user as to where to place a finger, when to slide a finger over a scanner, whether a scan was successful, etc. A second set of motivations are brand-related. For example, brand identification may be provided to a user, for example to assure the user that the sensor is an authentic product from a desired manufacturer, that the device in which the sensor resides is an authentic device from a desired manufacturer, to establish and build brand recognition among the user community as to the sensor or device in which the sensor is installed, etc. Still another set of motivations relate to providing visual interest to a device containing the sensor. To some, a colorful, illuminated device is simply more attractive and desirable than the alternative without illumination.
Today, visual indication associated with a fingerprint sensor is generally accomplished by disposing the sensor device in a separate housing that has a transparent or translucent indicator region or regions, and providing a light source such that at least a portion of the light produced shines through the transparent or translucent region. The transparent or translucent region may be a simple light “bar” or light “spot” or may be patterned to indicate a company name, design pattern of interest, and so forth.
The current methods of providing visual indication associated with a fingerprint sensor are relatively large. However, many of the most common devices into which fingerprint sensors are often installed, such as laptop computers, mobile telephones, personal digital assistant devices, etc. are often very compact, or require compact subassemblies (e.g., compact sensor devices). That is, there is pressure to reduce the size of the fingerprint sensor assembly. As current visual indication devices employ separate housings, light sources, sensor circuitry, and related connections, it is difficult if not impossible to significantly reduce the size of such assemblies.
Many current fingerprint sensors also include conductive bezels for driving a current into the finger being sensed. Examples of circuits employing bezels for this purpose are disclosed in U.S. Pat. No. 6,636,053 and U.S. Pat. No. 6,512,381, each of which being incorporated herein by reference. These bezels, which are often coplanar with the sensor surface, add to the overall size of the device. According to certain known designs, bezels are patterned with visual indicia, and a light source is provided for illuminating the pattern. The light source and bezel form a housing, and a molded fingerprint sensor is installed into such housing to obtain a fingerprint sensor and lighted bezel assembly. However, the separate bezel and light source housing are relatively large, and again, such an assembly can often result in an undesirably large final device. Furthermore, it is desired that the bezel be as physically close to the sensors as possible to optimize the sensitivity of the sensor. However, known separate illuminated bezel designs limit possible options of the sensor-to-bezel spacing.
Current visual indication devices also require a number of discrete assembly steps. As the number of discrete elements and manufacturing steps increase, manufacturing cost increases and the potential for faulty or inaccurate assembly that negatively affects product consistency, and yield losses increase. Discrete element sub-assembly is also a more time consuming process than integrated manufacturing. Thus, there is a need in the art for an improved design of a fingerprint sensor assembly which includes an integrated lighted indicator region.